ARTICLE 310: Conductors for General Wiring

NEC Tables 310.71, 310.73 and 310.75

Table 310.71 Ampacities of an Insulated Three-Conductor Copper Cable Isolated in Air Based on Conductor Temperatures of 90°C (194°F) and 105°C (221°F) and Ambient Air Temperature of 40°C (104°F)

Conductor Size (AWG or kcmil)

Temperature Rating of Conductor

2001 - 5000 Volts Ampacity

5001 - 35,000 Volts Ampacity

90°C (194°F) Type MV-90

105°C (221°F) Type MV-105

90°C (194°F) Type MV-90

105°C (221°F) Type MV-105

8

59

66





6

79

88

93

105

4

105

115

120

135

2

140

154

165

185

1

160

180

185

210

1/0

185

205

215

240

2/0

215

240

245

275

3/0

250

280

285

315

4/0

285

320

325

360

250

320

355

360

400

350

395

440

435

490

500

485

545

535

600

750

615

685

670

745

1000

705

790

770

860

Table 310.73 Ampacities of an Insulated Triplexed or Three Single-Conductor Copper Cables in Isolated Conduit in Air Based on Conductor Temperatures of 90°C (194°F) and 105°C (221°F) and Ambient Air Temperature of 40°C (104°F)

Conductor Size (AWG or kcmil)

Temperature Rating of Conductor

2001 - 5000 Volts Ampacity

5001 - 35,000 Volts Ampacity

90°C (194°F) Type MV-90

105°C (221°F) Type MV-105

90°C (194°F) Type MV-90

105°C (221°F) Type MV-105

8

55

61





6

75

84

83

93

4

97

110

110

120

2

130

145

150

165

1

155

175

170

190

1/0

180

200

195

215

2/0

205

225

225

255

3/0

240

270

260

290

4/0

280

305

295

330

250

315

355

330

365

350

385

430

395

440

500

475

530

480

535

750

600

665

585

655

1000

690

770

675

755

Table 310.75 Ampacities of an Insulated Three-Conductor Copper Cable in Isolated Conduit in Air Based on Conductor Temperatures of 90°C (194°F) and 105°C (221°F) and Ambient Air Temperature of 40°C (104°F)